Railway traffic controlling apparatus



Aug; 4, 1936.

c H. LAY 2,049,912

RAILWAY TRAFFIC CONTROLLING APPARATUS 4 Sheets-Sheet 1 Filed April 5, 1935 INVENTOR lzarlas Lay.

HE ATTOR N EY 1936- c; H. LAY 2,049,912

RAILWAY TRAFFIC CONTROLLING APPARATUS Filed April 5, 1935 4 Sheets-Sheet 2 INVENTOR Charles 117, Lay.

BY w g/T... '4

HA5 ATTORNEY Aug. 4, 1936. c H. Y 2,049,912

RAILWAY TRAFFIC CONTROLL ING APPARATUS Filed April 5, 1955 4 Sheets-Sheet 3 N lNVENTOR ClzarlasHLay 5Y 2% A.

HIS ATTORNEY Aug.4, 1936 c. H LAY RAILWAY TRAFFIC CONTROLLING APPARATUS Filed April 5, 19:55

4 Sheets-Sheet 4- INVENTOR Charles H. Lay.

HIS ATTORNEY Patented Aug. 4, 1936 UNITED STATES RAILWAY TRAFFIC CONTROLLING APPARATUS Charles H. Lay, Pittsburgh, Pa., assignor to The Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania Application April5, 1935, Serial No. 14,861

11 Claims.

My invention relates to railway traffic controlling apparatus, and particularly to apparatus for the automatic control of railway signals and/or train stopping devices. One feature of my invention is the provision of novel and improved means for giving more than three restrictive indications in the rear of a train.

I will describe one form of apparatus embodying my invention, and will then point out the novel features thereof in claims.

In the accompanying drawings, Figs. 1 and 1 when placed end to end with Fig. 1 on the left, constitute a diagrammatic View showing one form of apparatus embodying my invention; Fig. 2 is a diagrammatic view showing an alternative apparatus embodying my invention; while Fig. 3 is a view, partly diagrammatic, and partly an isometric projection, illustrating one form of relay suitable for use in the circuit arrangements shown in Figs. 1 1 and 2.

The structure of the relay shown in Fig. 3 will first be described and the circuits illustrated by Figs. 1 1 and 2 employing this type of relay will then be described. The relay of Fig. 3 comprises a main electromagnet A of the usual type having two parallel cores H and H connected together at their upper ends by a backstrap 30, and provided at their lower ends with enlarged pole pieces 2 and 2*, respectively. The core ll carries the usual operating winding 4 and an auxiliary winding 20 and the core ll likewise carries the usual operating winding 4 and an auxiliary winding 20, the windings 4 and 20 being similar in all respects to the windings 4 and 20 respectively. The windings 4 and 4 are connected in series to be cumulative in the usual manner, and are supplied with direct current from a suitable source, such as a battery 50, 40 through a pole-changer 60. The windings 20 and 20" are likewise connected in series to be cumulative for a purpose which will be described in detail hereinafter.

Attached to the rear sides of the pole pieces 2*- and 2 is a non-magnetizable bracket 10 which carries two pivot screws 80, only one of which pivot screws is visible in the drawings, and pivotally mounted on the screws 80 for swinging movement toward or away from the pole pieces 2 and 2 is a main tractive armature 90. 'A contact finger Hl is secured to, but insulated from, the under side of the armature 90, and is adapted to engage a fixed contact block HJ or lfl to close a contact lU -l B or In -10 in the usual and well-known manner.

Associated with the electromagnet A is a constantly magnetized core I I, here shown as a permanent magnet, the upper end of which engages the under side of the backstrap 30, and. the lower end of which is provided with a bifurcated pole 5 piece 42. Pivotally supported between the bifurcations of the pole piece 42 on terminal screws 43 screwed through the bifurcations, is a polarized armature 44 which extends equidistant through the pivot. The pole pieces '2 and 2 of the main electromagnet A are provided with integral extensions Ill and I5 respectively, the pole faces of which overlie the opposite ends of the armature 44, and it will be apparent, therefore, that the polarized armature 44 will swing toward one or the other of these extensions, depending upon the polarity of the current which is supplied to the windings 4 and 4 -When the polarized armature 44 is swung toward the extension l5, as shown, a contact finger I6 fastened to this armature by means of an insulating support 41 engages a fixed contact block 3 to close a contact Mi -I6 When the polarized armature is swung toward the extension [5 however, the contact finger l6 moves out of engagement with the fixed contact block l6 and into engagement with a fixed contact block Ili thus opening contact l6l6 and closing a contact Ili -I6 It should be noted that while, for purposes of illustration, I have shown the main and polarized armatures each provided with only one contact finger, these armatures may each be provided with as many other contact fingers as is desired.

The reference character B designates an aux- 35 iliary electromagnet comprising a pair of parallel cores l8 and I8 connected together at their upper ends by a magnetizable backstrap 49, and provided at their lower ends with enlarged pole pieces 2| and Zl having integral U-shaped extensions 22 and 22', respectively. Surrounding the cores I8 and 18 are windings 23 and 23', which windings, as here shown, are cumulatively connected in series. The windings 23* and 23 are also connected inseries with 45 the auxiliary windings 20 and 20 of the main electromagnet A, and externally controlled contacts Q; and it will be apparent, therefore, that with these contacts closed any change in flux in the coresof the main electromagnet will cause a current to fiow in the circuit including the windings 20 20 23 and 23 thus setting up a flux in the auxiliary electromagnet B. Cooperating with the pole pieces 2 l and 2 l and with the extensions 22* and 22 on these pole pieces 55 is an auxiliary armature 34 which is attached to the main armature by means of a non-magnetizable connecting member 45. The parts are so proportioned that when the main armature 90 is picked up, the auxiliary armature 34 will be mechanically held in an upper position in which it engages pole faces ze and. 26 formed on the under side of the pole pieces 2W and 2 l respectively, but that when the main armature 90 is released, the auxiliary armature 34 will then be moved to a lowermost position in which it rests on pole faces 2% and 27 formed on the extensions 222 and 22 of the pole pieces 2i and 2 l respectively.

As shown in the drawings, pole-changer B0 occupies an intermediate position in which the supply of current to the windings 4 and 4 of the main electromagnet A is cut oif, and this electromagnet is therefore deenergized. The auxiliary electromagnet B is therefore also deenergized, and armature 9D is accordingly released. Front contact Ill--lll controlled by armature 953 is therefore open and back contact Mi -Ni is closed. Furthermore, since armature 9% is released, auxiliary armature 34 occupies its lowermost position. Polarized armature 44 is swung toward extension l5 of pole piece 2, this being the normal position of this armature, and polar contact ltl6 is therefore closed, while polar contact l5 i6 is open. Armature 44 is in its normal position merely because the last operation of the relay was to that position.

In explaining the operation of the relay as a whole, I will first assume that pole-changer 6B is moved upwardly to what I shall term its normal position, thus supplying current of normal polarity to the windings 4 and 4 of the main electromagnet A. This current flowing in the windings i and 4 sets up a flux in the cores M and li and while this flux is building up, an electromotive force is induced in the windings 20 and 20* by transformer action, which electromotive force causes a current to flow in the windings 23 and 23 thus with contacts Q closed setting up a flux in the auxiliary electromagnet B. Since the auxiliary armature 34 occupies its lowermost position under these condi tions, the air gaps between this armature and the pole faces Zi and 2i on the auxiliary pole pieces 22 and 22 is considerably smaller than he air gaps between the auxiliary armature and the pole faces 25 and 2t on the pole pieces El and 2t and as a result the flux which is set up in the auxiliary electromagnet flows through the auxiliary armature 34 by way of the auxiliary pole pieces, thus exerting a force on the auxiliary armature tending to hold it in its lowermost position. This force is transmitted to the main armature through the relatively long lever arm afforded by the connecting member 45, and the parts are so proportioned that as long as the flux continues to build up in the cores H and li of the main electromagnet A, this force will be strong enough to prevent the main armature 99 from picking up. As soon, however, as the flux in the main electromagnet reaches a steady state, an electrornotive force is no longer induced in'the auxiliary windings 29 and 20 and the fiux in the auxiliary electromagnet then decays. When this happens, the force tending to hold the auxiliary armature 34 in its lowermost position is removed, and the main armature 99 will then pick up due'to the pull exerted on this armature by the main electromagnet. It follows, therefore, that the main armature 90 is considerably slower in picking up than would be the case if the auxiliary electromagnet and auxiliary armature were not provided. The energization of the main electromagnet A under the conditions just described will not aifect the polarized armature id since this armature already occupies its normal position.

I will next assume that with the parts in the positions in which they are shown in the drawings, the pole-changer Ell, instead of being moved upwardly to its normal position as just described,

is moved downwardly to what I shall term its reverse position, thus supplying current of re verse polarity to the electromagnet A. Under these conditions, the operation of the relay will be similar to that previously described with the single exception that since the main electromagnet A is now supplied with current of reverse polarity, the polar armature id, instead of remaining in the position shown, will swing to its reverseposition, thus opening contact 55 -45 and closing contact I6i6 If the relayis energized by current flow through itin, either direction at a time that contacts Q are open, the windings 23 and 23* will be unable to exert any influence on armature 35, accordingly the main armature fill will pick up immediately on the closure of a circuit through windings 4 and 4 and will immediately drop on a subsequent opening of the circuit. It will be apparent, therefore, that the armature 96 may be made quick or slow to actuate on any energization or deenergization'of windings i and 45,

depending on the open or closed condition of contacts Q.

' I will now assume that with pole changer 6t occupying either its normal or its reverse position, so that themain armature 90 is picked up, the polechanger is reversed to cause the polarized armature of the relay to reverse. During the reversal of the pole-changer, the flux in the cores M and li of the electromagnet A will rapidly drop to zero, and will then build up in the opposite direction, thus inducing an electromotive force in thewindings 2|], and 2% which will cause a flux to be set up in the cores us and 68 of the electromagnet B in the manner previously described. Since armature 9|] is now picked up, auxiliary armature 34 will occupy its upper position, and the air gaps between this armature and the pole faces 26" and 26 on the under side of the pole pieces 2| and 2| of the auxiliary electromagnet will be considerably smaller than the air gaps between this armature and the pole faces El and 27 on the auxiliary pole pieces 22 and 22 As a result, the flux which is set up in the cores of the auxiliary electroinagnet B will now flow through the armature 34 by way of the main pole pieces 2 e and 2N, thus exerting a pull on this armature which acts through the connecting member $5 to prevent the main armature 98 from dropping. It follows that armature 90 will remain picked up during the reversal of the polarity of the current supplied to magnet A.

Having made clear the operating characteristics of the polarized relays which I employ, the circuits illustrated in Figs. 1" and l will now be described. The reference character E designates a railway track along which trafiic normally moves in the direction indicated by the arrow. The rails of this track are divided by the usual insulated joints '6 to form a series of track sections I2, 2-3, etc. Each section is provided with a track circuit. and these track circuits, as

here shown, are of the center-fed type, comprising a battery 1 connected across the rails at an intermediate point in the section, and two track relays T and AT connected across the rails at the entrance and exit ends, respectively.

Each section is provided with two polarized relays A and B preferably. of the type illustrated in Fig. 3, an approach lighting relay L, and a battery C.

Each two adjoining sections are provided with a line circuit which includes, in series, relay A for the forward section and relay B for the rear section, and current of normal or reverse polarity is supplied to such circuit according as the B relay for the section next in advance of the forward section is closed or open. Referring to sections 3-4 and 45, for example, the line circuit for these sections passes from the plus terminal of battery C3, through the front point of contact I3 of relay 3B, front contact M of track relay 4AT, winding of approach lighting relay 3L, front contact l of relay lT, winding of relay 4A, front point of contact it of track relay EAT, front point of contact ll of track relay 5T, winding of relay fiB, front point of contact ill of track relay 5T, front point of contact is of relay 5AT, front point of contact 26 of relay 4T, front point of contact 2i of relay AT, and the front point of contact 22 of relay 33, to the minus terminal of battery C3. Relay 313 being closed, the current which is supplied to this circuit is of normal polarity, ielay 3L is energized, relays 5A and 5B are both energized in the normal direction and the polar contacts of the two latter relays are therefore swung to the left. When relay 3B is open, and the line circuit just traced is closed at all other points, current of reverse polarity is supplied thereto, because of the fact that contacts l3 and 22 of relay 3B function as a pole-changer. Relays AA and 513 will then be energized in the reverse direction, so that their polar contacts will be swung to the right.

Each section is provided with a signal S comprising two groups of lamps. The upper group is made up of a green lamp GA, a yellow lamp YA, and a red lamp RA. The lower group is similarly made up of a green lamp GB, a yellow lamp YB, and a red lamp RB. Referring particularly to signal S3, when relays 3A and 3B are both energized in the reverse direction, as shown in the drawings, and when approach lighting relay 3L is deenergized, the yellow lamp YA of the upper group will be lighted, the circuit being from I the plus terminal of a battery C3, through back contact 8 of relay 3L, front point of contact ll of relay 3A, polar contact H of relay 3A in the reverse position, and lamp YA of signal S3 to the minus terminal of battery C3. The yellow lamp YB of the lower group in this signal will also be lighted, the circuit being from the plus terminal of battery C3, through back contact 8 of relay 3L, front point of contact 9 of relay 3B, polar contact ill of relay 3B in the reverse position, and lamp YB to the minus terminal of battery C3.

When relay 3A becomes energized in the normal direction, lamp GA of signal G3 will become lighted by virtue of a circuit which will be obvious from the drawings. Similarly, when relay 33 becomes energized in the normal direction, lamp GB will become lighted by virtue of a circuit which will be obvious from the drawings. In response to deenergization of relay 3A, red lamp RA will become lighted, the circuit being from the plus terminal of battery C3, through back contact 8 of relay 3L, back point of contact H of relay 3A,

and lamp'RAto the minus terminal of battery C3. Similarly, when relay 33 opens, red lamp RB will become lighted by virtue of a circuit which will be obvious without detailed explanation. It is understood, of course, that all lamps of signal S3 will be extinguished except when the approach lighting relay SL is deenergized. The controlling circuits for each of the signals are similar to those which have been traced for signal S3.

As shown in the drawings, an automatic train stopping device D is provided for each track section, and this device is provided with a clearing circuit which is closed when and only when both of the polarized relays A and B for the associated section are energized in the normal direction. Considering the device D3 for section 2-3, for example, the clearing circuit for this device is from one terminal of its operating winding through polar contact N3 of relay 3B in the normal position, front contact 26 of the same relay, front neutral contact 2? of relay 3A, and polar contact lid of relay 3A in the normal position, to the other terminal of the operating winding for the device D3.

' As shown in the drawings, the section to the left of point i is occupied by a train F, so that track relay ET is open. The circuits for relays EA and US are therefore open, so that these relays are deenergized. If approach lighting relay lL were deenergized, due to the presence of a train in section i2, the red lamps RA and RB of signal Si would both be lighted. Relay 1B being open, relays 2A and 3B are energized in the reverse direction. Relay 2B is deenergized because its circuit is open at track relay IT. Relay ZB being open, relays 3A and iB are energized in the reverse direction. Relay 3B being closed, relays 5A and 5B are energized in normal direction. Relay 5A is energized in the normal direction because relay AB is closed.

At point 2, then, relay 2A is energized in the reverse direction, so that lamp YA of signal S2 is lighted; and relay 2B is deenergized, so that the lamp RB of signal S2 is lighted. (It is assumed at this point, and at all similar points hereinafter, that the approach lighting relay for each signal is deenergized due to the train approaching such signal). This signal then indicates that the second section in advance is occupied. At point 3, both relays 3A and 3B are energized in the reverse direction, so that the'yellow lamps YA and YB of signal 83 are both lighted. Signal S3 indicates, therefore, that the third section in advance is occupied by a train. Relay AA being energized in the normal direction, lamp GA of signal S4 is lighted, and relay 43 being energized in the reverse direction, lamp YB of this signal is also lighted. Signal Sfil then indicates that the fourth section in-advance is occupied by a train. Relays 5A and 5B are both energized in the normal direction. It follows that both of the green lamps of signal S5 are lighted, so that this signal indicates that the four blocks in advance are unoccupied.

When a train moving toward the left enters section l5, it will open track relay 5T, and the contacts ill and it of this relay will then exclude relay 53 from its circuit and will close an auxiliary path for relay tA, which path includes a resistance 24 to take the place of relay 5B. It follows that relay AA will remain energized. Similarly, when the train advances into the section to the point at which track relay 5A1 will open, contacts i6 and E9 of this relay will close another branch for the line circuit of relays 4A and 5B, which branch includes a resistance 24, with the result that relay 4A will still remain energized. Of course, the opening of relay 5T will open the circuit for relay 5A, and the opening of relay EAT will again open the circuit for relay 5A at another point.

In describing the structural details of the type of polarized relay I employ it was explained that auxiliary windings 20 20 23 and 23 were employed to make the neutral armature of such relays slow to pick up and slow to drop away unless disabled by the opening of contacts Q. These auxiliary windings are represented in the circuit drawings by a single loop designated with the numeral 23.

The A relays, as herein employed, have the loop 23 permanently closed and therefore the neutral contacts of these relays are at all times slow to pick up and slow to release. Because of this characteristic the front point of contact ll of these relays always remains closed on the reversal of current flow through them and prevents the momentary closure of a circuit through the RA lamp at such time.

Similarly, owing to their slow pick-up characteristic, the contact II will remain in engagement with its back point during momentary energizations of the relay, which may occur under various conditions, and prevent the momentary interruption of the RA signal circuit and the momentary completion of the GA or YA signal circuit. Such an operation of the A relay may, for example, occur when a short train goes over a cut section.

The B relays, as herein employed, in addition to controlling signals, are employed as a polechanging relay. It is desirable, when the circuit of a B relay is opened, that it drop its polechanging contacts without delay so that, should a very short train clear the section immediately to the rear, the current supply through the A relay in the section immediately to the rear and the B relay in the second section to the rear will be immediately energized in the reverse direction to give a following train the proper restrictive indication without delay. If the polechanging contacts of the B relay of the forward section are slow to drop, under the assumed circumstances, the current flow through the A and B relays of the rear sections will momentarily be in the normal direction before contacts l3 and 22 have had time to drop and will accordingly give a less restrictive indication before giving the desired more restrictive indication in response to their energization in the reverse direction. This possible objection is overcome by opening the auxiliary circuit of the B relay at contacts I00, corresponding to contacts Q of Fig. 3, of the track relay of the forward section at the same time that its main winding is opened by such track relay.

The circuits shown in Fig. 2 are very similar to those shown in Figs. 1 and 1 the only difference being in the operation of the A and B relays in multiple instead of in series. The multiple arrangement has the advantage that necessity for use of external resistances such as 23 is avoided, and higher resistance line relays may be employed.

In the alternative scheme shown in Fig. 2, the

circuits are applied to the track sections and signals shown in Fig. l and the condition of the circuits are the same. This figure may accordingly be placed to the right of Fig. 1 in substitution for Fig. 1*. Each two adjoining sections of Fig. 2 are provided with a line circuit which includes, in multiple, instead of in series, relay A for the forward section and relay B for the rear section. Current of normal or reverse polarity is supplied to such circuit according as the B relay for the section next in advance of the forward section is closed or open. Referring to sections 34 and 45, for example, the line circuit for these sections passes from the plus terminal of battery C3, through the front point of contact I3 of relay 3B, front point of contact M of track relay AAT, winding of relay 3L, front point of contact l5 of relay 6T, winding of relay 4A, the front points of contacts 26 and 2i of track relays 4T and lAT, respectively, and the front point of contact 22 of relay SE to the minus terminal of battery C3. The relay AA in picking up closes an operating circuit for relay 5B in multiple with that traced through 4A. The circuit of relay 5B extends from the left terminal of relay AA, via the front point of contact 25 of relay AA, the front points of contacts l6 and ll of track relays EAT and ET, respectively, the winding of relay 5B, the front points of contacts l8 and E9 of track relays 5'1 and SAT, respectively, to the right terminal of relay 4A. The relay 33 being closed, the current which is supplied to relays 4A and 5B is of normal polarity, so that relay 3L is energized when relays 4A and 5B are both energized in the normal direction. The polar cont acts of the latter relays are therefore swung to the left. When relay 3B is open, and the circuits of relays AA and 5B are otherwise prepared, current of reverse polarity is supplied first to relay 4A, and on its picking up, is extended to the relay 5B. Relays 4A and 5B will, accordingly, be energized in the reverse direction, so that their polar contacts will be swung to the right.

It will be apparent that the signal and train stopping device circuits of the modified arrangement are identical to those shown in Figs. 1 and 1 and. that any further description of these circuits will therefore be unnecessary.

In the arrangement shown in Fig. 2, when a train moving toward the left enters section l-5, it will open track relay 5T, and the contacts I! and I8 of this relay will open the circuit of relay 5B which was heretofore closed through contacts 25 of relay 'lA. When the train advances into the section to the point at which track relay 5T will open, the latter relay will likewise open the circuit of relay 5A, and the subsequent opening of relay BAT will also open the circuit for relay 5A at another point.

The operation of the apparatus during the progress of the train through the succeeding sections shown in the drawings will be obvious from the foregoing without further explanation.

The train stopping devices D may, of course, be omitted, if desired, and the same thing is true of the approach lighting relays.

Although I have herein shown and described only one form of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination, a railway track divided into P sections, a first and a second polarized relay for each section, means including slow-acting polechanging contacts on the first relay of each section operating according as such relay is energized or deenergized to supply current of normal the forward section and the first relay of the r-ear or reverse polarity to the second relay of the section next in the rear and to the first relay of the second section in the rear, track circuits for the sections including track relays for the control of said polarized relays, and traffic governing means for the sections controlled by said polarized relays.

2. In combination, a railway track divided into sections, a first and a second polarized relay for each section, a line circuit for each two adjacent sections including in series the second relay of the forward section and the first relay of the rear section, means including a set of slow-acting polechanging contacts on the first relay of the section next in advance of such forward section for supplying each of said line circuits with current of normal or reverse polarity according as said last specified relay is energized or deenergized, track circuits for the sections including track relays for the control of said line circuits, and traffic governing means fo the sections controlled by said polarized relays.

3. In combination, a railway track divided into sections, a first and a second polarized relay for each section, means including slow-acting polechanging contacts on said first relay operating according as such relay is energized or deenergized to supply current of normal or reverse polarity to the second relay of the section next in the rear and to the first relay of the second section in the rear, track circuits for said sections including track relays for the control of said polarized relays, and traffic governing means for the sections controlled by said polarized relays.

4.. In combination, a railway track divided into sections, a first and a second polarized relay for each section, a line circuit for each two adjacent sections including in series the second relay of the forward section and the first relay of the rear section, means for supplying each of said circuits with current of normal or reverse polarity according as the first relay of the section next in advance of such forward section is energized or deenergized, said means including slow-acting pole-changing contacts on said last specified relay, a track circuit for each section including a track relay having front contacts included in the two line circuits of the section, a shunt around the first relay of each section including a back contact of the track relay of such section, and signals for the sections controlled by said polarized relays.

5. In combination, a railway track divided into sections, a first and a second polarized relay for each section, a line circuit for each two adjacent sections including in series the second relay of the forward section and the first relay of the rear section, a source of current for supplying each of said circuits, means including slow-acting polechanging contacts on the first relay of the section next in advance of such forward section for connecting said source to said circuit in one manner or another to actuate the relays in said circuit in a normal or reverse direction according as such first relay is energized or deenergized, means operating when any one section is occupied by a train to open the line circuits including both the first'and second relays of such section and to close a branch path for the circuit including the second relay of the section next in advance, and trafiic governing means for the sections controlled by said polarized relays.

6. In combination, a railway track divided into sections, a first and a second polarized relay for each section, a line circuit for each two adjacent sections including in series the second relay of section as well as an approach lighting relay for the section hex-tin advance of such forward section, means including a set of slow-acting polechanging contacts on the first relay of such sec- 5 tion in advance of such forward section for supplying each of said circuits with current of nor- 'mal or reverse polarity according as such relay is energized or deenergized, track circuits for the sections for the control of said line circuits, and signals for said sections controlled by said polarized and approach lighting relays.

7. In combination, a railway track divided into sections, a first and a second polarized relay for each section, means including slow-acting polechanging contacts on the first relay of each section according as such relay is energized or deenergized to supply current of normal or reverse polarity to the second relay of the section next in the rear and to the first relay of the second section in the rear, track circuits for the sections including track relays for the control of said polarized relays, a train stopping device for such section, and a clearing circuit for each device closed if and only if both the first and second relays of the associated section are energized in normal direction.

8. In combination, a railway track divided into sections, a first and a second polarized relay for each section, a line circuit for each two adjacent sections including the second relay of the forward section with the first relay in multiple therewith through contacts of said second relay, means including the first relay of the section next in advance of such forward section for supplying each of said line circuits with current of normal or reverse polarity according as said last specified relay is energized or deenergized, track circuits for the sections including track relays for the control of said line circuits, and traffic governing means for the sections controlled by said polarized relays.

9. In combination, a railway track divided into sections, a first polarized relay for each section having slow acting neutral contacts in addition to the usual polar contacts, a second polarized relay for each section also having slow acting neutral contacts in addition to the usual polar contacts, other neutral contacts on the second polarized relay for each section for supplying current of normal or reverse polarity to the second polarized relay of the section next in the rear and to the first polarized relay of the second section in the rear, track circuits for said sections including track relays for the control of said polarized relays, and traific governing means for the sections having circuits including the neutral and polar contacts of one of said polarized relays as well as certain of the neutral and all of the polar contacts of the other of said polarized 6 relays.

10. In combination, a railway track divided into sections, a first and a second polarized relay for each section, means including slow-acting polechanging contacts on the first relay of each sec- 65 tion operated according as such relay is energized or deenergized to supply current of normal or reverse polarity to the second relay of the section next in the rear and to the first relay of the second section in the rear, another relay, track 70 circuits for the sections including track relays for the control of said polarized relays and said other relay, and traffic governing means for the sections controlled exclusively by said latter relays.

11. In combination, a railway track divided into sections, a first and a second polarized relay for each section, a line circuit for each two adjacent sections including in multiple the second relay of the forward section and the first relay of the rear section, means for supplying each of said relays with current of normal or reverse polarity according as the first relay of the section next in advance of such forward section is energized or deenergized, track circuits for each section including a track relay having front contacts included in the circuit of the first relay of the associated section, and signals for the sections controlled by said polarized relays.

CHARLES H. LAY. 

